Citrate-modified biochar for simultaneous and efficient plant-available silicon release and copper adsorption: Performance and mechanisms.

Silicon (Si) deficiency and heavy metals (HMs) pollution are common for farmland soil because of long-term intensive farming. In this study, a novel citrate-modified biochar (C-BC) was introduced as a soil conditioner to simultaneously increase the amount of plant-available Si (PASi) and immobilize HMs. The maximum amount of PASi released was 33.00 mg⋅g-1 from C-BC pre-treated with 0.1 mol⋅L-1 citrate (C-BC0.1). A formation-transport coupling mechanism for increasing the amount of PASi released was developed. Stable Si in the biomass was pyrolyzed to give silicate that was relatively mobile via nucleophilic attack of citrate and hydrolysis of amorphous Si. Silicate species were then released through the porous surface and widening cracks caused by pyrolysis. At citrate concentrations >0.1 mol⋅L-1, the surface and cracks were easily blocked by precipitates formed during pyrolysis. The ability of C-BC to remove HMs was assessed using Cu as an example. C-BC0.1 was optimal for adsorbing Cu, and the maximum adsorption capacity was 271.73 mg⋅g-1. The Cu adsorption mechanism mainly involved surface precipitation, surface complexation, electrostatic attraction and hydrogen bonding. Our research provides important implications for simultaneously addressing Si deficiency and HMs contaminant problems by these materials for soil amendment in agro-ecosystem.

Timely identification of atypical acute aortic dissection in the emergency department:a study from a tertiary hospital

Background/aim: Acute aortic dissection (AAD) is a rare but fatal disease if left untreated. Symptoms are often similar to common conditions; therefore, the diagnostic strategy is important. We aimed to identify the atypical symptoms in a timely manner without putting patients at greater risk for undetected AAD. Materials and methods: We conducted a retrospective observational study of 59 AAD patients with both atypical and typical symptoms from January 2012 to December 2016. Patients with atypical symptoms continuing more than 30 min underwent a D-dimer test and computed tomography (CT) or computed tomographic angiography (CTA). Results: Of the 59 AAD patients, 22 were atypical. In the atypical group, the median delay time in our hospital was 3.1 h; average delay time after July 2015 was shorter than average delay time before June 2015 (16.59 ± 24.70 vs. 1.90 ± 0.57 h, P = 0.076). Conclusions: For patients in the emergency department who are suspected of having AAD, incorporating atypical symptoms with high levels of D-dimer into a triage strategy could improve the efficiency of clinical decision making. Furthermore, essential education directed towards the recognition of the atypical symptoms of AAD for front-line physicians may aid in a timely diagnosis, as compared with the usual assessments in the emergency department.

Pyrene biodegradation with layer-by-layer assembly bio-microcapsules.

Biotechnology is considered as a promising technology for the removal of polycyclic aromatic hydrocarbons from the environment. Free bacteria are often sensitive to some biotic and abiotic factors in the environment to the extent that their ability to effect biodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is hampered. Consequently, it is imperative to carry out investigations into biological systems that will obviate or aid tolerance of bacteria to harsh environmental conditions. Chitosan/alginate bio-microcapsules produced using layer-by-layer (LBL) assembly method were tested for pyrene (PYR) biodegradation under harsh environmental conditions. Morphology observation indicated that the flake bio-microcapsules could be successfully prepared through LBL assembly method. Surface analysis showed that the bio-microcapsules had large fractions of mesopores. The results of the biodegradation experiments revealed that the 95% of 10mgL-1 PYR could be removed by the bacteria encapsulated chitosan/alginate bio-microcapsules in 3 days, which was higher than that of the free bacteria (59%). Compared to the free cells, the bacteria encapsulated chitosan/alginate bio-microcapsules produced 1-6 times higher PYR biodegradation rates at a high initial PYR concentration (50mgL-1) and extremely low pH values (pH =3) or temperatures (10°C or 40°C), as well as high salt stress. The results indicated that bacteria in microcapsules treatment gained a much higher tolerance to environmental stress and LBL bio-microcapsule could be promising candidate for remediating the organic pollutants.

[Discriminant Analysis of Lavender Essential Oil by Attenuated Total Reflectance Infrared Spectroscopy].

This work aimed to use attenuated total reflectance Fourier transform infrared spectroscopy to identify the lavender essential oil by establishing a Lavender variety and quality analysis model. So, 96 samples were tested. For all samples, the raw spectra were pretreated as second derivative, and to determine the 1 750-900 cm(-1) wavelengths for pattern recognition analysis on the basis of the variance calculation. The results showed that principal component analysis (PCA) can basically discriminate lavender oil cultivar and the first three principal components mainly represent the ester, alcohol and terpenoid substances. When the orthogonal partial least-squares discriminant analysis (OPLS-DA) model was established, the 68 samples were used for the calibration set. Determination coefficients of OPLS-DA regression curve were 0.959 2, 0.976 4, and 0.958 8 respectively for three varieties of lavender essential oil. Three varieties of essential oil's the root mean square error of prediction (RMSEP) in validation set were 0.142 9, 0.127 3, and 0.124 9, respectively. The discriminant rate of calibration set and the prediction rate of validation set had reached 100%. The model has the very good recognition capability to detect the variety and quality of lavender essential oil. The result indicated that a model which provides a quick, intuitive and feasible method had been built to discriminate lavender oils.

Activation persulfate for efficient tetrabromobisphenol A degradation via carbon-based materials: Synergistic mechanism of doped N and Fe.

In this study, a novel carbon-based material (Fe-N-PGWBC) utilizing the garden waste, melamine and FeSO4 as the precursor was successfully synthesized, efficiently activating peroxydisulfate (PDS) to degrade tetrabromobisphenol A (TBBPA). Under typical conditions (Fe-N-PGWBC dose of 100 mg·L-1, PDS of 0.2 mM and TBBPA of 10 mg·L-1), Fe-N-PGWBC/PDS system could achieve over 99% TBBPA removal (including adsorption and degradation) within 60 min, and the corresponding rate constant ks was 0.0724 min-1, which was almost 40.2 times higher than that of the pristine biochar. The extraction experiments implied that the excellent adsorption performance of Fe-N-PGWBC did not hinder the degradation of TBBPA. Abundant active sites (rich oxygen-containing functional groups, Fe-O and Fe3C) of Fe-N-PGWBC could effectively promote PDS decomposition to produce reactive oxygen species. The probe-based kinetic modelling methods verified that approximately 87.6% TBBPA was degraded by SO4·-, 12.2% TBBPA was degraded by 1O2, and 0.2% TBBPA was degraded by ·OH. Furthermore, based on the calculation of density functional theory and identification of products, TBBPA was mainly involved in three transformation pathways including hydroxylation, debromination and ß-scission process. The study proposed a facile resource approach of garden waste and provided deeper understanding for the TBBPA degradation mechanisms in heterogeneous system.

Complete genome sequence of Brucella canis strain 118, a strain isolated from canine.

Brucella canis infects several species of animals, and canine is the preferred host. Genome sequences of strains from different hosts are valuable for comparative analysis of host adaptation and microevolution. Here, we report the genome sequence of Brucella canis strain 118, a strain isolated from canine.

Discovery of novel SecA inhibitors against "Candidatus Liberibacter asiaticus" through virtual screening and biological evaluation.

"Candidatus Liberibacter asiaticus" (Ca. L. asiaticus) is the causal agent of Huanglongbing disease of citrus and current study focuses on the discovery of novel small-molecule inhibitors against SecA protein of Ca. L. asiaticus. In this study, homologous modeling was used to construct the three-dimensional structure of SecA. Then, molecular docking-based virtual screening and two rounds of in vitro bacteriostatic experiments were utilized to identify novel small-molecule inhibitors of SecA. Encouragingly, 93 compounds were obtained and two of them (P684-2850, P684-3808) showed strong antimicrobial activities against Liberibacter crescens BT-1 in bacteriostatic experiments. Finally, molecular dynamics simulations were employed to explore the binding modes of the receptor-ligand complexes. Results in MD simulations showed that compound P684-3808 was relatively stable during simulation, while compound P684-2850 left the binding pocket. Compound P684-3808 might be suitable as a lead compound for further development of antimicrobial compounds against SecA of Ca. L. asiaticus.

Bio-resolution of glycidyl (o, m, p)-methylphenyl ethers by Bacillus megaterium.

A newly isolated Bacillus megaterium with epoxide hydrolase activity resolved racemic glycidyl (o, m, p)-methylphenyl ethers to give enantiopure epoxides in 84-99% enantiomeric excess and with 21-73 enantiomeric ratios. The (S)-enantiomer was obtained from rac-glycidyl (o or m)-methylphenyl ether while the (R)-epoxides was obtained from glycidyl p-methylphenyl ether. The observations are explained at the level by enzyme-substrate docking studies.

Mutations of the TERT promoter are associated with aggressiveness and recurrence/distant metastasis of papillary thyroid carcinoma.

Several previous studies have shown that mutations in B-Raf proto-oncogene (BRAF) and telomerase reverse transcriptase (TERT) can be used for the diagnosis and prognosis of papillary thyroid carcinoma (PTC). However, whether mutations in BRAF and the TERT promoter may improve the accurate identification and risk stratification of high-risk patients in the early stage of PTC remains unclear and requires further investigation. In the present study, mutations in BRAF and the TERT promoter were examined in 205 patients using PCR and Sanger DNA sequencing. The potential association between mutations in these two genes and the clinicopathological characteristics of patients with PTC was then analyzed. BRAF mutations were identified in 169/205 (82.4%) patients, whereas only 8/205 (3.9%) patients presented mutations in the TERT promoter, seven patients exhibited a C228T mutation, and the remaining one had a C250T mutation. There were 6/205 (2.9%) patients with mutations in both BRAF and the TERT promoter. Importantly, compared with patients with no mutations, patients with mutations in BRAF were more likely to exhibit mutations in the TERT promoter. A significant difference in lymph node metastasis was found between the BRAF V600E mutation group and the group without mutations in BRAF. Mutations in the TERT promoter were significantly correlated with older age, extrathyroidal invasion, tumor multifocality and advanced tumor/node/metastasis stage, which are associated with the aggressiveness of PTC. Moreover, compared with patients exhibiting mutations in BRAF, mutations in the TERT promoter were found to be significantly associated with aggressive clinicopathological features and higher risk of recurrence or distant metastasis. Collectively, mutations in the TERT promoter were not frequent, but were significantly correlated with more aggressive clinicopathological features of PTC. Therefore, mutations in the TERT promoter may be an important factor in the genetic background of PTC, and detection of such mutations may help the accurate identification and management of high-risk patients with recurrent or distant metastasis.

[The immunogenicity and safety of 10 microg recombination yeast hepatitis B vaccine applied in expanded population].

OBJECTIVE: To assess the feasibility of the 10 microg recombination yeast hepatitis B vaccine in the expanded applicable population group aged 5 - 18. METHODS: People with both HBsAg and anti-HBs negative were selected to take two-stage clinical experiment and the safety and immunogenicity were observed. Safety observation was conducted in 925 subjects, while 568 for immunogenicity. The observation group (aged 5 - 18) included 493 subjects, and (age > 18) 75 enrolled in control group. For the observation group, there were three sub-groups including a child group (141, aged 5 - 6), early youth group (177, aged 12 - 13), and youth group (175, aged 16 - 18). Both groups were administered with 10 microg recombination yeast hepatitis B vaccines with 3 doses at 0 month, 1st month, 6th month. To assess the immunogenicity, the vaccination reactions were observed during the following 4 weeks in order to assess the vaccine safety. The blood samples were taken during 4 - 6 weeks after fully vaccinated, and then anti-HBs were tested with RIA and analyzed by comparing the positive rate of anti-HBs, the geometric mean titer (GMT) and the protective rate between the two groups. RESULTS: Both observation and control group didn't show any general reactions, adverse events following immunization (AEFI) or coincidental cases when observed at 0.5 h, 6 h, 24 h, 48 h, 72 h, 1 week, 2 weeks, 3 weeks, 4 weeks after being vaccinated. The result of serum test showed, the positive rates of child group, early youth group, youth group and control group were respectively 100.00% (141/141), 97.18% (172/177), 98.29% (172/175) and 89.33% (67/75); the GMTs of anti-HBs were respectively 440.28, 875.38, 467.80, 131.06 U/L; the protective rates were respectively 100.00% (141/141), 97.18% (172/177), 97.14% (170/175) and 86.67% (65/75). The positive rate, GMT and protective rate of the experimental group were all higher than that of control group (chi(2)(positive rate) = 12.77, 5.12, 7.99; t(GMT) = 3.89, 4.13, 5.91; chi(2)(protective rate) = 16.81, 8.60, 8.44; P < 0.05). CONCLUSION: This vaccine could be expanded to 5 - 18 year-old population with safety and effectiveness, the positive rate and protective rate of anti-HBs were both higher than that of control group.

Induction chemotherapy plus IMRT alone versus induction chemotherapy plus IMRT-based concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma: a retrospective cohort study.

BACKGROUND: To evaluate the value of concurrent chemotherapy after induction chemotherapy for locoregionally advanced nasopharyngeal carcinoma (NPC) in the era of intensity-modulated radiation therapy (IMRT), we performed this retrospective cohort study to compare the efficiency and toxicities of induction chemotherapy plus IMRT alone (IC + RT) versus induction chemotherapy plus IMRT-based concurrent chemoradiotherapy (IC + CCRT). METHOD: We analyzed data from patients with locoregionally advanced NPC (stage III-IVb) who were treated at the West China hospital between January 2008 and December 2014. Patients received docetaxel, cisplatin, and 5-fluorouracil (TPF) IC followed by IMRT alone (IC + RT group) or IMRT plus cisplatin concurrent chemotherapy (IC + CCRT group). The main endpoint was overall survival (OS), which was evaluated by the Kaplan-Meier method and log-rank test. Multivariate Cox proportional hazard analysis was used to identify potential independent prognostic factors. Treatment-associated toxicities were compared between groups using the Chi squared test. RESULTS: A total of 78 patients treated with IC + RT and 76 with IC + CCRT were analyzed. The median follow-up time was 59 months (range: 7-108 months). There was no difference between patients treated with IC + RT and IC + CCRT in terms of 3-year OS (89.0% versus 88.0%, p = 0.286), progression-free survival (76.8% versus 80.0%, p = 0.142), locoregional recurrence-free survival (87.1% versus 90.5%, p = 0.156), or distant metastasis-free survival (83.6% versus 82.6%, p = 0.567). Treatment (IC + RT versus IC + CCRT) was not an independent prognostic factor for OS (HR 1.425, 95% CI 0.698-2.908; p = 0.331). IC + CCRT was associated with a higher incidence of grade 3-4 neutropenia than IC + RT during radiotherapy (11.8% versus 1.3%, p = 0.020). CONCLUSION: IC plus IMRT alone achieves similar patient survival outcomes as IC plus IMRT-based concurrent chemoradiotherapy, and has a lower incidence of toxicity.

Determination of the solubility parameter of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate by inverse gas chromatography.

Thermodynamic properties of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] BF4) were determined via inverse gas chromatography (IGC). Two groups of solvents with different chemical natures and polarities were used to obtain information about [BMIM] BF4-solvent interactions. The specific retention volume, molar heat of sorption, weight fraction activity coefficient, Flory-Huggins interaction parameter as well as solubility parameter were also determined in a temperature range of 333 - 373 K. The results showed that the selected solvents n-C10 to n-C12, carbon tetrachloride, cyclohexane and toluene were poor solvents for [BMIM] BF4, while dichloromethane, acetone, chloroform, methyl acetate, ethanol and methanol were favorite solvents for [BMIM] BF4. In addition, the solubility parameter of [ BMIM] BF4 was determined as 23.39 (J/cm3)0.5 by the extrapolation at 298 K. The experiment proved that IGC was a simple and accurate method to obtain the thermodynamic properties of ionic liquids. This study could be used as a reference to the application and research of the ionic liquids.

[Determination of thermodynamic parameters for ionic liquid 1-hexyl-3-methylimidazolium trifluoromethansulfonate by inverse gas chromatography].

The thermodynamic parameters of ionic liquid 1-hexyl-3-methylimidazolium trifluoromethansulfonate ([HMIM] OTF) were investigated by inverse gas chromatography in the temperature range of 343.15-373.15 K. Eighteen probe solvents were used to calculate the molar enthalpy of sorption, molar enthalpy of mixing at infinite dilution, molar enthalpy of vaporization and the mass fraction activity coefficients. Furthermore, Flory-Huggins interaction parameters, the solubility parameter of the ionic liquid were calculated to judge the interactions between [HMIM] OTF and the 18 probes solvents. The results showed that among the selected solvents, n-C6-9, tetrahydrofuran, diethyl ether, cyclohexane and benzene are the poor solvents for [HMIM] OTF, while dichloromethane, acetone, chloroform, ethyl acetate, carbon tetrachloride, methyl acetate, toluene and methanol are the favorite solvents for [HMIM] OTF. In addition, the solubility parameter of [HMIM] OTF at room temperature (298.15 K), which was obtained by linear extrapolation method, was 20.74 (J/cm3)0.5. This study could be used as a reference to the application and research of the ionic liquids.

[Characterization of surface properties of 1-allyl-3-methylimidazolium chloride ionic liquid by inverse gas chromatography].

The determination of the dispersive component of surface free energies (gamma(s)d) at different temperatures and Lewis acid-base parameters of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM]Cl) were investigated by means of inverse gas chromatography (IGC). Four n-alkanes, including n-hexane (C6), n-heptane (C7), n-octane (C8) and n-nonane (C9), were chosen as the apolar probes to characterize the dispersive component of the surface free energies at 343.15, 353.15, 363.15 and 373.15 K, respectively; and dichloromethane (DCM), trichloromethane (TCM), tetrahydrofuran (THF), ethyl acetate (EtAc), acetone (Acet) as the polar probes to estimate the Lewis acid-base parameters to judge the interactions between [AMIM] Cl and the solvents. The IGC characterizations encompassed the adsorption thermodynamic parameters to acid-base surface interactions, including the standard enthalpy (deltaHa(s)) and the free energy change of adsorption (deltaGa(s)) at different temperatures. The results showed that the Lewis acid parameter Ka of [AMIM] Cl was 0.34, and the base parameter Kb was 1.68, which indicated it was Lewis amphoteric with predominantly basic character. Furthermore, the free energy of adsorption deltaGa(s) was also figured out. It was found that the gamma(s)d of the [AMIM] Cl were 52.26, 50.82, 46.08 and 42.05 mJ/m2 at 343.15, 353.15, 363.15 and 373.15 K, respectively. The results are of great importance to the study of the surface properties and the application of ionic liquid.

Dielectric Boundary Force in Molecular Solvation with the Poisson-Boltzmann Free Energy: A Shape Derivative Approach.

In an implicit-solvent description of molecular solvation, the electrostatic free energy is given through the electrostatic potential. This potential solves a boundary-value problem of the Poisson-Boltzmann equation in which the dielectric coefficient changes across the solute-solvent interface-the dielectric boundary. The dielectric boundary force acting on such a boundary is the negative first variation of the electrostatic free energy with respect to the location change of the boundary. In this work, the concept of shape derivative is used to define such variations and formulas of the dielectric boundary force are derived. It is shown that such a force is always in the direction toward the charged solute molecules.

Enantioselective hydrolysis of glycidyl methylphenyl ethers by Botryosphaeria dothidea ZJUZQ007: effect of substitution pattern on enantioselectivity.

Resolution of racemic glycidyl (o, m, p)-methylphenyl ethers by using a newly isolated Botryosphaeria dothidea ZJUZQ007 with epoxide hydrolase activity affords enantiopure epoxides with enantiomeric excesses (e.e.(s)) of 91-99% and enantiomeric ratios (E) of 18.1 to 48.6. The (R)-enantiomer was obtained from rac-glycidyl (o or m)-methylphenyl ethers whereas the (S)-epoxides was obtained from glycidyl p-methylphenyl ether. Substitution pattern of the methyl group exerted effects both on configurations of the remaining epoxides and enantioselectivities of epoxide hydrolase. The observations were explained by enzyme-substrate docking studies. It is the first example showing that for kinetic resolution of glycidyl methylphenyl ethers, fungal species of B. dothidea was applied.

[Determination of solubility parameters of high density polyethylene by inverse gas chromatography].

Inverse gas chromatographic (IGC) technology was used to determine the solubility parameters of high density polyethylene (HDPE) at the absolute temperatures from 303.15 to 343.15 K. Six solvents were applied as test probes including hexane (n-C6), heptane (n-C7), octane (n-C8), nonane (n-C9), chloroform (CHCl3) and ethyl acetate (EtAc). Some thermodynamic parameters were obtained by IGC data analysis such as the specific retention volumes of the solvents (V(0)(g)), the molar enthalpy of sorption (delta H(S)(1)), the partial molar enthalpy of mixing at infinite dilution (delta H(1)(infinity)), the molar enthalpy of vaporization (delta H(v)), the activity coefficients at infinite dilution (omega (1)(infinity)), and Flow-Huggins interaction parameters (X(1,2)(infinity)) between HDPE and probe solvents. The results showed that the above six probes are poor solvents for HDPE. The solubility parameter of HDPE at room temperature (298.15 K) was also derived as 19.00 (J/cm3)(0.5).